It is known to produce foam from a reactive mixture of one or more polyols and one or more isocyanates, for example as disclosed in U.S. Pat. No. 6,034,197, which is incorporated herein in its entirety by reference. Suitable systems for making and/or dispensing such foams are described, for example, in U.S. Pat. Nos. 5,186,905; 5,255,847; 5,950,875; 6,811,059; 6,929,193; and 6,996,956, each of which is incorporated herein in its entirety by reference. However, in some instances it may be desirable to make foam without the need to use isocyanate reactants, such as those used in formulating polyurethane foams.